Water quality

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This article is awaiting a an exciting review of performance metrics for different types of low impact developmentA stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. BMPBest management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls.. Updates will be posted throughout 2018.

Overview

Improvements in the quality of stormwater runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface. is one of the primary benefits of low impact developmentA stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. strategies. Although some chemical changes occur inside the practices, much of the pollution reduction of low impact developmentA stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. strategies comes from runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface. reduction. i.e. diverting excess water through infiltration or evapotranspiration.

Nutrients

Plants (including algae) require three macro nutrients to grow: Nitrogen, potassium, and phosphorus. Of these three, phosphorus is the often the "growth-limiting" nutrient. i.e. the local environmentRefers to the conditions in which an organism lives and survives or the conditions in which an organism resides. These conditions can be described as aspects of a “physical”, “social” or an “economic” environment, depending on the perspective perceived by the observer. may have an abundance of nitrogen and potassium, but algae won't develop unless phosphorus is available too. Phosphorus

Heavy metals

The heavy metals noted as particularly harmful to aquatic ecosystems are:

  • Chromium(Cr),
  • Lead (Pb),
  • Copper (Cu), and
  • Zinc (Zn)[1]
  • Laboratory experiments on bioretentionA shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation. media have demonstrated that the organic matter significantly improves retention of lead (Pb), copper (Cu), and zinc (Zn) [2]. This research also found that extended detentionA stormwater design features that provides for the gradual release of a volume of water in order to increase settling of pollutants and protect downstream channels from frequent storm events. of the stormwater in the cell did not improve this water quality benefit.
  • Cores of media were extracted from five 10 year old bioretentionA shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation. cells in Queensland, Auz and tested for a suite of heavy metals: “Although trace amounts of several heavy metals (most prominently Mn and Zn) were found in most of the basinsGround depression acting as a flow control and water treatment structure, that is normally dry., all heavy metal levels found in the soil were either below detectable limits, or within acceptable limits based on legislated health-based investigation levels.”[3]

    For review

https://docs.wixstatic.com/ugd/eff3d3_e441b4b0954a4d2297f0e7fc077ed1a4.pdf

See Also

Winter

External Links


  1. Feng W, Hatt BE, McCarthy DT, Fletcher TD, Deletic A. Biofilters for Stormwater Harvesting: Understanding the Treatment Performance of Key Metals That Pose a Risk for Water Use. Environ Sci Technol. 2012;46(9):5100-5108. doi:10.1021/es203396f.
  2. Gülbaz S, Kazezyilmaz-Alhan CM, Copty NK. Evaluation of Heavy Metal Removal Capacity of Bioretention Systems. Water Air Soil Pollut. 2015;226(11). doi:10.1007/s11270-015-2640-y.
  3. Lucke T, Nichols PWB. The pollution removal and stormwater reduction performance of street-side bioretention basins after ten years in operation. Sci Total Environ. 2015;536:784-792. doi:10.1016/j.scitotenv.2015.07.142.